The red circles explode on the map. They detonate slowly at first, one or two at a time. And then faster and faster. Soon they're appearing so quickly and in such magnitude that the entire map of San Francisco is covered in a pale red sheen, from the Sunset District to South Beach.

Each explosion represents a number of families kicked out of their homes through an Ellis Act eviction. The bigger the circle, the more units evicted. To the right of the map a timeline counts down, running through every month since 1997 when SF landlords began using the Ellis Act to get rid of tenants.

Finally the clock ticks to the most recent years. The biggest circles yet burst across the page, a sea of red. The clock slows, and settles at December 29th, 2013. The final tally of families kicked out of their homes reaches 3811.

The project consists of 25 or so volunteers who collect data on evictions in San Francisco, ranging from individual stories to statistics from government organizations. Once the data is cleaned and formatted, it's turned into visualizations for the public.

"Digital maps and storytelling make the often invisible processes of eviction, displacement, and gentrification tangible and accessible," Erin McElroy, the project's director told me.

McElroy, who is also one of the key organizers of the anti-Google Bus protests, created the organization after months of helping her friends shlep their belongings after no-fault evictions. "I have a friend who joked we should have started our own moving company," McElroy says ruefully. She estimates she knew more than 40 people who were evicted before she started the mapping project.

Some of them were forcibly evicted through the Ellis Act. Others were bribed. "A buyout is when a landlord threatens to do an Ellis Act and offers money under the table,'" McElroy says. "If you're poor or working class, a lot of people would rather take the money and leave if they know they're going to get forced out anyways." (City of San Francisco law guarantees a minimum of $5,265.10 relocation compensation per tenant, up to a maximum of $15,795.27 plus $3,510.16 per elderly or disabled tenant.)

McElroy had recently wrapped up a master's program in Social and Cultural Anthropology, where she had documented the displacement of Romas (colloquially known as gypsies) in Romania. She found it strange to go from witnessing the fates of Romas, pushed into the garbage dumps on the outskirts of town, to return to California and watch her own friends forced out of their homes.

"In the beginning it was just me with the mapping project, in March 2013," McElroy says. She started attending community meetings to learn more about the evictions happening and soon realized no one was documenting the tales of the evicted. "At that time, it was hard to get a reporter to write about any of these stories."

The longer McElroy spent on the project, the more volunteers joined her. At this point McElroy is overseeing five different subcommittees and 25 volunteers, including three interns from a Stanford Urban Studies class. The volunteers are working on a variety of projects, from collecting oral histories of those who have been evicted to centralizing data from different SF housing organizations.

They've released two additional maps which didn't capture quite as much media attention as the first one: No-Fault Evictions and Ellis Act Evictions Against Seniors and People with Disabilities.

Now, the Mapping Project is turning its attention to building a searchable database, where SF residents can look to see the history of their building and their landlord, allowing them to track whether anyone has been Ellis Acted out of their own building.